1. Field of the Invention
This invention relates generally to novel hindered phenol substituted trisaryl-1,3,5-triazines and the use thereof to protect against degradation by environmental forces, inclusive of actinic radiation, high temperature, oxidation, moisture, atmospheric pollutants and combinations thereof.
2. Description of Related Art
Exposure to sunlight and other sources of ultraviolet radiation are known to cause degradation of a variety of materials, especially a polymeric materials. For example, polymeric materials such as plastics often discolor and/or become brittle as a result of prolonged exposure to ultraviolet light. Accordingly, a large body of art has been developed directed towards materials such as ultraviolet light absorbers and stabilizers which are capable of inhibiting such degradation.
A class of materials known to be ultraviolet light absorbers are trisaryl-1,3,5-triazines, in which at least one of the aryl rings has a hydroxyl group ortho to the point of attachment to the triazine ring. In general this class of materials is well known in the art. Disclosures of a number of such trisaryl-1,3,5-triazines can be found in the patent literature. For example, U.S. Pat. No. 3,843,371 discloses hydroxyphenyltrizines for use in photographic materials. The triazines in this patent, however, show poor solubilities and poor stabilities.
U.S. Pat. No. 3,896,125 discloses hydroxyphenyl triazines, but these, too are poorly soluble and discolor with time.
Typically, the aforementioned aryl ring with the hydroxyl group ortho to the point of attachment to the triazine ring is based on resorcinol and, consequently, this aryl ring also contains a second substituent (either a hydroxyl group or a derivative thereof) para- to the point of attachment to the triazine ring. For example, U.S. Pat. Nos. 3,118,837 and 3,244,708 disclose p-alkoxy-o-hydroxyphenyl triazines with improved UV protection, but such triazines also exhibit poor solubility and poor long-term stabilities.
However, there remains a need for triazine UV absorbers which impart yellowing resistance to polymers, both under high temperature conditions and upon exposure to actinic radiation. The novel hindered phenol substituted trisaryl-1,3,5-triazines of the present invention satisfy that need.